


Flashpoint

by Murderspark



Category: Undertale (Video Game)
Genre: Gen, Headcanon Origins, Prequel
Language: English
Status: In-Progress
Published: 2016-04-27
Updated: 2016-04-27
Packaged: 2018-06-04 22:51:57
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,700
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6678574
Author URL: https://archiveofourown.org/users/Murderspark/pseuds/Murderspark
Summary: <blockquote class="userstuff">
              <p>Pre Undertale. Sans walks a knife's edge of bravado and obedience to keep his brother out of the clutches of their creator.</p>
            </blockquote>





	Flashpoint

**Author's Note:**

> It has been years since I've been moved to write fan fiction, but these characters just won't leave me be. Expect some rust and some serious headcanon verging on AUishness. Enjoy!

Sans shuffled irritably through the complex. Interns and other researchers cleared a wide berth for the short skeleton. He was always amiable with them, but they sensed his mood readily. The only monsters who crossed his path were those damned color bleached fanatics, and they  _ leered _ as he passed.

 

He flicked his badge at the door's sensor lock. Magnetic parts clanked and choking hot air blasted him in the face. Gaster's personal lab was always sweltering. Sans made a vow that should he and his brother ever leave the capital, they were going to the coldest place he could find.

 

The doors slammed shut behind him as he wandered through the royal scientist's personal playground. To call it massive was a disservice. In terms of sheer space, it rivaled the king's own castle, or so he had been told.

 

Questionable liquids burbled away over burners long forgotten. Open books were strewn haphazardly across desks and tables alike. Here and there, huge transparent panels in the flooring allowed him to look down into the sluggish magma below. 

 

It didn't take very long for him to find Gaster, however. The tall skeleton was fixated on the screen in front of him. Sans could see the readouts. Stress testing a soul. He wondered, and not for the first time, if the king really understood what these borrowed souls went through down here. 

 

Gaster languidly ran a phalange over a series of switches, shutting the machine down. He could almost  _ feel _ the grin stretch across the madman's face.

 

“ **Ah, Sans…”** He crooned.

 

Sans snorted angrily. “g, what do you want? i'm busy.”

 

“ **Too busy to humor your creator with your presence?”** Gaster whirled on the smaller skeleton, closing much of the distance between them.

 

Exasperated, Sans spread his hands in a gesture of surrender. “i'm here, aren't i?”

 

The doctor cocked his head to the side ever so slightly.  **“You don't have much of a choice in the matter.”**

 

“dings, we've been over this. you'll go after my brother. i'll try to kill you. you'll try to kill me.” Sans' pupils disappeared. “bad times for everyone.”

 

They both still bore the scars from their one and only 'bad time.' The royal scientist's face, which had been almost handsome previously, was a melted, cracked mess. Sans' own injuries weren't so visible. His vitality had suffered terribly, but the doctor didn't know that. It was imperative to keep up that front.

 

“ **So good of you to remember.”** Gaster hissed. **“You've been neglecting your research.”**

 

Sans shrugged, his pupils winking back into existence. “no, i've been neglecting  _ your _ research.  _ my _ research is coming real well.”

 

“ **That time manipulation nonsense? With that blithering intern?”** Gaster scoffed. **“There are more important subjects to focus on, or have you forgotten our agreement?”**

 

The short skeleton clinched his teeth. “how could i, g? you do your best to remind me.”

 

They'd come to terms shortly after Papyrus had been 'born.' His brother had no knowledge of their creator's existence. Papyrus had never been a part of any of the crazed skeleton's experiments, but the price…

 

Well, Sans had been a very good guinea pig for a long time.

 

“ **Good.”** A crooked grin. **“I'm certain all my summons were destroyed?”**

 

Sans had the grace to look at least a little embarrassed.

 

“ **Ignoring my orders, of course, is a breach of our terms.”** The royal scientist purred. **“Allowing your defiance to go unpunished would be… damaging to my reputation.”**

 

A cold shard of panic collected in Sans' chest. “g, i don't have the time for this. alphys and i are so close to a breakthrough...”

 

The tall skeleton sighed.  **“Your research is of no consequence to me. The barrier is my only concern.”**

 

Sans fought the urge to roll his eyes. The barrier was Gaster's constant fixation. Even the construction of the Core, which benefited all monsterkind, was just another piece in play for that goal. The doctor's obsession with the world beyond knew no bounds.

 

“the barrier will most definitely still be there when alphys and i are done. can't this wait?” Sans appealed.

 

Gaster's eyes grew dim in reverie.  **“When we die, Sans, what then?”**

 

The raw words caught him off guard, and it took a considerable effort to keep his face blank. Sometimes,  _ sometimes _ , their relationship was almost amicable. There were brief, fleeting moments when their interactions were almost warm. But this…

 

They didn't do feelings. They didn't do philosophy. Personal stuff was off limits. They sure as hell didn't lay bare insecurities. If it had been Pap, he'd have responded with comfort, but Gaster? He settled on apathy.

 

He shrugged. “the world breathes a collective sigh of relief? we're abominations, dings.”

 

The distant look in the taller skeleton's eyes snapped away in a haze of anger. A twisted smirk pulled at warped features, and Gaster leaned in uncomfortably close. Sans stood his ground, fighting the urge to put distance between them.

 

“ **Oh? Even Papyrus?”** He hissed.

 

A wave of furious magic rose in his gut. Sans shoved it down and locked it away, swallowing his hateful anger. Insults lobbed at him meant nothing. Insults aimed at Papyrus… He didn't handle those well.

 

“pap is different, g.” Sans snapped.

 

The doctor reared up to his full height and towered threateningly over his creation. Sans  _ might _ have hit a nerve there. Baiting him was probably stupid, but it was a fantastic coping mechanism. His perpetual grin widened.

 

“ **He is. Unfortunately, we will never know exactly how different, will we?”** Gaster snarled.

 

If there was anything that pissed ol' Dings off, it was the fact that Sans had kept him away from Papyrus. He considered it his one shining success in life. 

 

“no. we won't.” Sans' tone was blunt.

 

Fine, furious tremors wracked the taller skeleton's frame for a few moments before he lapsed into eerie stillness. Gaster's eye sockets slid shut, and he turned away from Sans, granting some much appreciated distance.

 

The silence seemed to stretch for hours, broken only by the soft slither of the hem of Gaster's coat along the tiles as the doctor made his way to one of the massive windows that overlooked the lava flow. He drummed his phalanges on the sill absentmindedly.

 

Sans grimaced and eyed the royal scientist impatiently. Gaster was very good at wasting his time - _ hah, time _ \- when he was working on anything important. He managed to keep his mouth shut long enough for Gaster to finally shatter the quiet.

 

“ **I am not willing to rot under this mountain. I WILL NOT moulder in this place. We WILL bring that wretched barrier down.”** The words held an ugly vehemence.

 

The short skeleton rolled his shoulders. Maybe they could get down to the point of it now.

“i'm guessin' you have a plan, dings?” Sans inquired.

 

Gaster turned, and the room darkened, making the pinpoint lights of his pupils all the more vibrant. Sans' hands found their way to his pockets. When the doctor's focus sharpened, the area around him lost its brightness and the air would chill.

 

“ **You know what we are, Sans. We, or rather our bodies, were human once.”** His tone was deadly serious.

 

Sans' brow furrowed. He wasn't quite sure where Dings was going with this line of thought, but the lead in was enough to foster a sense of worry deep in his gut.

 

“g, no matter what our bodies were, our souls aren't human.” Sans pointed out.

 

The doctor waved his hand dismissively,  **“** **And yet… With a proper environment, could they become human-like? Human-like enough for the spell?**

 

Sans sighed. His role in his creator's new scheme was becoming pretty apparent.

 

“you could run this test on yourself, you know.” The short skeleton complained.

 

“ **I could, but I will not. You've ignored my orders for nearly a month now. The rebellion cannot stand without some sort of consequence.”** Gaster declared flatly.

 

_ And you don't wanna die if it blows up in your face. Can't leave that part out, eh? _

 

“of course.” If he hadn't been so livid, Sans would have been very proud of himself for keeping his reply almost civil.

 

“ **Suspend your research and make whatever arrangements you need to with your brother. Be here tomorrow morning.”** Gaster turned his back to him once more, clearly releasing him.

 

Sans sneered, turning on his heels. It was classic Dings to conjure up some wildly inane concept and subject him to it. It was all well and fine to risk death or maiming for the smallest percentage of success as long as Gaster himself was in no danger.

 

The thought made him wonder, not for the first time, what kind of fiend created the doctor himself. It was plain that they weren't natural monsters in any sense. He couldn't fathom what kind of person made Gaster into the twisted creature he was today.

**  
** “d ings… who made  _ you _ ?” The words fell out of Sans' mouth before he had a chance to reign them in.

 

Sans eyed the royal scientist over his shoulder. Gaster still had his back to him and had fallen into that deep stillness. The tall skeleton clinched his hands behind his back, looking more like a statue than a living thing.

 

Just as Sans had given up hope for an answer, the doctor's voice broke the silence. His tone was flat and clinical at best.

 

“ **A** **long time ago when monsters lived above ground, there was a fool human who fell in love with a beautiful monster woman. A** _ **boss**_ **monster, no less. She was his world.**

 

** Humanity does not look kindly on what it does not understand. One day, his village turned on him. They fell upon the human, wounding him mortally. **

 

**How he managed to crawl his way back to his angel, he did not know, but his lover** _**poured** _ **magic into him. She** _**willed** _ **him to live. Without a care for her own safety, she filled the dying human with all the magic she had. Her soul faltered, and she died.**

 

**The human also died that day. Whether or not he** _**stayed** _ **that way is a different story...”**

 

Sans left the lab without another word.


End file.
